1. Field of the Invention
The present invention relates to a centrifugal force-based microfluidic device, and more particularly, to a centrifugal force-based microfluidic device in which a fluid and particles are separated from a sample, including the fluid and the particles, within a disc-shaped platform using a centrifugal force such that the separated fluid is quantitatively distributed, and a microfluidic system including the centrifugal force-based microfluidic device.
2. Description of the Related Art
In general, a microfluidic structure of a microfluidic device includes a chamber in which a small amount of fluid is confined, a channel through which the fluid flows, a valve that regulates the flow of the fluid, and several functional units that perform predetermined functions using the fluid and which may also include a basic structure such that a chamber, a channel, and a valve are combined. The arrangement of the microfluidic structure is disposed on a chip-shaped substrate so that a test involving a biochemical reaction can be performed on a small chip, which is referred to as a bio chip. Further, a device is manufactured so that the processing and manipulation of several steps can be performed on one chip, which is referred to as a lab-on-a chip.
A driving pressure is needed to convey the fluid within the microfluidic device. A capillary pressure or a separate pump generates this driving pressure. These days, microfluidic devices, in which microfluidic structures are disposed on a compact disc-shaped platform and which drive a fluid using a centrifugal force, have been suggested, and are also referred to as a Lab CD or a Lab-on a disk. However, since these microfluidic devices are not fixed on a frame, but instead rotated, these devices are different from a Lab-on a chip, which operates while being fixed on the bottom of a frame in several aspects. It is easy to perform a centrifugal separation operation using a centrifugal force, but it is difficult to drive a separate valve or make a local temperature adjustment.
However, in the fields of biochemistry, biology, and medical science in which the microfluidic device is typically used, these microfluidic devices are required to have the function of separating particles from a sample, such as a biological sample of blood, saliva, and urine, in which a fluid and the particles are mixed. In order to meet such requirements, U.S. Pat. No. 5,061,381 has been proposed. However, the microfluidic device disclosed therein is stilled required to perform the function of separating the particles and the fluid in a small region within a disc-shaped platform. Furthermore, the microfluidic device is required to have the function of quantitatively distributing the fluid that is separated without going through a metering step involving the use of an additional unit.